Foreign ground item with wedge-shaped reinforcement in the boundary region

ABSTRACT

A sub-base element ( 1 ), for example a shower tray base element, for designing a floor-level overall system. An essential component of such sub-base elements is generally a carrier element made of a rigid foam core, which has lower pressure resistance than the floor region surrounding the sub-base element. If the surrounding floor region and the sub-base element are not directly covered with a load-distributing and deformation-rigid layer, such as a covering made of floor tiles, but rather, for example, with a flexible covering, such as PVC, the rim zone of the carrier element constitutes a problem region. Notably with loads that are introduced in substantially punctiform manner, such as when passing over the edge with a wheel chair wheel, for example, frequent load changes in the edge region of the carrier element can result in mortar spalling beneath the flexible covering and in permanent deformation of the carrier element.

The invention relates to a sub-base element, for example a shower tray base element, for designing an overall floor-level system wherein the sub-base element is either inserted in a compatible depression in a floor covering having high pressure resistance, or the sub-base element is first placed on an unfinished floor and the floor covering having high pressure resistance, such as a floor pavement, is then applied adjoining the sub-base element, and wherein the sub-base element has a layer structure as follows: a core layer made of plastic foam, the pressure resistance of which is less than that of the aforementioned floor covering, a water-resistant transition layer which is glued to the core layer and comprises an adhesive layer containing a textile strengthening structure, such as a non-woven fabric, woven fabric or laid scrim, and a highly pressure-resistant mortar layer as the cover layer on the transition layer, the top of mortar layer being planar or having a gradient.

Sub-base elements, which can be multi-layer building boards for applying of material in a planar manner, are known in various designs. Such building boards are notably used in equipping sanitary areas with floor-level shower tray elements.

DE 20 2010 003 760 U1 discloses such a coated building board, comprising a core layer made of moisture-resistant foamed material, which has a layer used as the support layer, on at least one supporting side, and which comprises:

-   -   a thin transition layer applied to the core layer;     -   a non-woven fabric layer made of glass fibers; and     -   a composite layer made of pressure-resistant, hardened coating         mortar.

In general, the sub-base element used as a shower tray base element is only installed in the region of the shower itself. The region formed by the shower tray base element is thus surrounded by a floor covering, which is generally a floor pavement. The floor covering and shower tray base element are generally covered with a covering having uniform thickness and collectively form a floor-level system having no differences in height. A similar arrangement can be found in spaces for toilets for the disabled.

This base is typically stepped on by people with their feet. The load caused by the weight of the person is distributed over the foot contact area. Floor-level shower systems, however, are particularly suited to use by a person sitting in a wheel chair. In this case, the total weight of the person and wheel chair exerts a high pressure, or point load, on the subsurface which is acted upon via the wheel contact areas, which are relatively small as compared to foot contact areas.

This generally does not present problems if the subsurface is a load-distributing and deformation-rigid layer, such as, for example, a covering made of ceramic tiles or flagstone.

For hygienic reasons, it is particularly advantageous to equip certain applications, such as sanitary areas in hospitals, swimming pools, or stalls for the disabled, with a continuous, flexible covering, such as PVC. However, such a covering transfers the load acting thereon directly to the subsurface located beneath, without any further distribution.

The drawback of the building board known from DE 20 2010 003 760 U1 is that the composite layer composed substantially of mortar, which for cost and weight reasons is kept relatively thin in comparison with the core layer, is not unconditionally suitable for absorbing point loads, without the possibility of any resulting deformation in the plastic range, or irreversible break-up of the rigid bonds between the individual structures contained in the mortar which were created in connection with the setting of the mortar. This break-up of the bonds can also be referred to colloquially as detachment, or spalling, of the edges.

Based on experience, the edges of the mortar-coated building boards which adjoin the boundary of the floor covering on which a person steps or on which a wheel chair rolls are particularly at risk.

DE 101 31 338 A1 also makes known a shower base element, which is made of rigid foam and is used to implement a floor-level shower, which has a preferably central outlet, wherein a surface of the shower base element is covered with a sealant. According to the invention, a groove, which opens toward the top of the shower base element and employs material reinforcement, is formed in the region the rim of the shower base element, and a rim of the groove that is associated with the rim edge extends at a distance (a) from the rim edge.

The drawback of this embodiment is that, not only is production of the groove complex, but the reinforcing mortar layer is present only inside the groove. In contrast, the rim surrounding the groove is made of relatively soft rigid foam, as compared to the mortar layer present in the groove.

The mortar layer (see reference numeral (15), FIGS. 6 and 7 in DE 101 31 338 A1) applied above the rim edge is consequently not reinforced. Point loads occurring in this region, which are not distributed to other regions via a load-distributing layer, but rather are transferred directly to the mortar located beneath, for example when placing a flexible covering on the mortar cover layer, may result in detachment, or spalling, of the edges, or damage to the edges, in the unreinforced region of the rim edge, and consequently in irreversible damage. Next to the groove, on the exterior side of the carrier element made from rigid foam, a rigid foam region will thus always remain, which extends directly under the covering applied thereon. The mortar-reinforced groove thus does not produce a reinforcing effect directly on the rim of the carrier element, but only where the groove starts. The region between the groove and the base surrounding the carrier element is not reinforced.

DE 10 2006 046 437 B3 describes a carrier element for mounting barrier-free shower areas, which is provided with a groove-like recess within the rim region, as is also disclosed in DE 101 31 338 A1. This groove can initially be closed with a dummy piece during installation of the shower tray. After the floor covering has been applied and grouted, the dummy piece can be removed, allowing the glass panel of a static lateral part to enter at a later point.

Moreover, a second recess can be provided parallel to the first recess. This recess can be used to compensate for any intentional or unintentional difference in height between the surface of the floor covering applied to the carrier element and the surface of the floor covering surrounding the carrier element, in that a suitable flat or angular section is inserted in the recess.

If the carrier element having no static lateral part is to be used for a shower partition, those recesses that are not required are filled with a corresponding mortar compound.

While a groove filled with mortar compound constitutes a reinforcement of the carrier element, similarly to the carrier element disclosed in DE 101 31 338 A1, this reinforcement is not disposed directly on the critical rim region, but rather spaced therefrom. To the extent that the carrier element and the region surrounding the carrier element are not provided with a deformation-rigid layer, such as, for example, a covering made of tile, but for example only with a flexible covering, such as one using PVC, the rim zone of the carrier element is formed by the region adjoining the groove-like recess. As differs from the groove filled with mortar compound, this region is only suitable for absorbing point loads to a very limited extent.

It is therefore the object of the invention to design a multi-layer sub-base element such that, not only can the mortar layer covering the plastic foam core layer be implemented in a substantially thin manner, and thus in a cost-effective and easy manner, but the mortar layer will be thicker in problem zones, and notably in the rim regions toward the outside edge of the sub-base element, resulting in a more pressure-resistant/deformation-rigid design, without additional steps. Because similar problems can also occur in the rim region of the opening in sub-base elements which are implemented as shower base elements, and which therefore generally contain a opening for a drain pan, another object of the invention is to offer a solution in the form of a reinforced design.

This object is achieved by providing the core layer, together with the transition layer located thereon, on at least one outside edge length (L_(A)) and/or on at least one inside edge length (L_(I)) of the sub-base element, with at least one graduation, and by thickening the mortar layer, which is planar at the top or has a gradient, in the region of the graduation, so that there is no significant difference in pressure resistance, or deformation resistance, between the surrounding floor covering and the sub-base element.

The situation is that the floor covering, which covers the unfinished floor and surrounds the sub-base element, is installed so as to be at least as thick as the sub-base element, and thus has considerably higher pressure resistance and deformation resistance than the unit comprising the core layer of the sub-base element and the covering mortar layer. This strength difference increases with reductions in thickness of the sub-base element mortar layer. Because of the substantially non-elastic nature of the mortar layer, individual and recurring load changes negatively affect the adhesive bond structure of the mortar itself and the adhesive bond structures between the different cover layers. Such load changes occur, for example, when a wheelchair wheel passes over the boundary between the floor covering and sub-base element and suddenly transfers the point load acting in the region of the wheel contact surface to the mortar edge of the sub-base element.

Because of the reinforcement of the mortar layer in the region of the critical edge according to the invention, the difference in strength and resistance in relation to the bending strain properties between the floor covering and sub-base element is reduced.

It is preferable for the boundary region of the graduation to be made from the compacted material of the core layer. At least some of the material originally present in the region of the opening is not mechanically removed, for example by means of cutting, milling or severing, and instead is compacted. Compaction takes place by applying high pressure to the region intended for the opening. For this purpose, the pressure to be introduced must be so high that the core layer deforms irreversibly, whereby the opening is preserved even after the pressure is removed.

It is particularly advantageous if not only one, but several graduations are provided. For this purpose, proceeding from the highest thickness of the mortar layer on the outside edge, the layer is incrementally reduced to the thickness of the mortar layer provided in the central region.

Instead of a large number of graduations, it is advantageous, from a manufacturing point of view, to implement a wedge-shaped bevel. Such a bevel, to which the mortar layer is applied in a wedge-shaped tapering manner, is also advantageous in that the pressure resistance does not need to be incremental, but rather decreases linearly, which is to say from a high value on the outside edge to a lower value, which is required in the central region of the sub-base element, which is characterized by a uniform mortar layer thickness.

It is advantageous for the angle of the bevel to be greater than 10° and less than 45°. A smaller bevel angle will result either in the thickness of the mortar layer on the sub-base element edge being insufficient, or in a longer, and thus heavier, mortar wedge region. A bevel angle larger than 45° lowers the pressure resistance gradient over a very short distance from a high to a low value and, as a result, load changes that occur can have a disadvantageous impact.

So as to reduce the variants that can be formed by sub-base elements that are reinforced only on one side, it is advantageous, notably with sub-base element having a non-square configuration, for the entire periphery of the sub-base element to be provided with one or more graduations, and therefore with a rim-side mortar thickening.

It is further advantageous for a load-bearing reinforcement/strengthening to be introduced in the mortar layer in the region of the graduation or bevel, because the pressure resistance in the critical rim region of the sub-base element is thus increased.

This reinforcement can be a mat, a woven fabric, a laid scrim or the like. Both textile structures and geometries made of plastic materials or glass fibers are possible materials for this purpose. Also suitable are reinforcements made of material strips arranged in bundle form, as well as strips or profiled sections made of composite material. One example of such a composite material is a material commercially offered by Bosig GmbH under the name of “Phonotherm”, which is a polyurethane-based plastic material, to which auxiliary agents such as aluminum foil particles are added.

It is particularly advantageous to design the reinforcement as a plastic or metal rail, which is preferably connected to the element, because this rail is cost-effective to m procure, since it is a standard product, and easy to handle, particularly when applying it to the rigid foam layer and surrounding it with mortar.

If a reinforcement made of an angle section is used as the reinforcement element, the combination of high resistance moment and easy handling create a particularly advantageous form of strengthening. The reinforcement is to be applied to the graduation or bevel so that it is completely enclosed by the mortar layer to be applied.

In a further embodiment of the invention, the sub-base element is not inserted as a prefabricated unit in a depression introduced in the floor covering, but rather is created at the installation site. For this purpose, a kit according to the invention is used, which comprises a sub-base element, for example a shower tray base element, wherein the sub-base element contains a core layer made of plastic foam, the pressure resistance of which is lower than that of the aforementioned floor covering, and a water-resistant transition layer, which is glued to the core layer, wherein the core layer, together with the transition layer located thereon, is graduated or beveled to the outside on at least one edge length of the sub-base element. The kit further comprises a packaged mortar substance for mixing, which is to be applied on-site to the core and to transition layers as mortar paste, and which results in a highly pressure-resistant mortar layer, which is planar at the top or has a gradient, as the cover layer on the transition layer, a mortar layer thickened in a wedge shape being obtained in the region of the graduation or bevel, so as to preclude an excessive difference in pressure resistance between the flooring level to the sub-base element.

The contour of the sub-base element is preferably quadriform, however other shapes, for example round or polygonal shapes, are also possible.

EXEMPLARY EMBODIMENT

The invention will be described in more detail hereafter based on an exemplary embodiment illustrated in the drawing.

The figures in the drawings show:

FIG. 1: a perspective view of the core layer of a sub-base element in an embodiment for a shower base element;

FIG. 2 a section according to the line I-I in FIG. 1;

FIG. 3 a sub-base element having a three-layer structure and a mortar layer that is thickened in a wedge shape in the rim zones;

FIG. 4 a sectional view of the connecting region between the shower base element and the adjoining floor covering;

FIG. 5 a partial section of a sub-base element having a mortar reinforcement with single graduation;

FIG. 6 a partial section of a sub-base element having a mortar reinforcement with multiple graduations; and

FIG. 7 a partial section of a sub-base element having a mortar reinforcement that is beveled in a wedge shape and a reinforcement designed as an angle section.

FIG. 1 shows the core layer 2 of a sub-base element 1 in an embodiment for a shower base element comprising a peripheral ridge 15 and a wedge-shaped bevel 17 that slopes, at an angle α₁, toward an outside edge 16, and a peripheral ridge 18, from which a likewise wedge-shaped bevel 19 slopes toward an opening 5 at an angle α₂. The angles α₁ and α₂ are preferably identical. The bevels 17 and 19 in this exemplary embodiment extend along all four edge lengths L_(A) and L_(I).

The ridge 15 slopes to the other side toward the ridge 18 at an angle β₁. The angle β₁ is approximately 1° and is preferably identical to the angle β₂ of the surface of the mortar layer 4, shown in FIG. 3. The gradient resulting from the angle β₂ guides water that is introduced through a shower head (not shown) to a drain pan 9, which is disposed in the opening 5.

While the mortar layer 4 is thickened in a wedge shape in the region of the bevels A, at an angle α₁ or α₂, this is preferably designed to have a constant thickness in the region B.

FIG. 3 shows a sub-base element 1 having a three-layer structure. The core layer 2 corresponds to the core layer shown in FIG. 1 and forms the first layer. This layer is covered by a water-resistant transition layer 24, which is glued to the core layer 2 and contains a non-woven fabric 3. The cover layer of the sub-base element 1 is formed from a high-strength mortar layer 4 which is provided with a gradient β₂ toward the opening 5.

FIG. 4 shows the sub-base element 1 inserted in a depression 6. The depression 6 is compatible with the sub-base element 1 and is formed by way of an opening in a floor covering 8, which is installed on an unfinished floor 7. The sub-base element 1 and the depression 6 together form a clearance fit, whereby the sub-base element 1, in the inserted state, is surrounded by a gap 21 having an average width of approximately 5 mm.

The depth of the depression 6 corresponds at least to thickness of the sub-base element 1. If the sub-base element 1 is a shower base element, either the entire depression 6, or at least depression 6 in the region of the drain pan 9, has a depth resulting from adding the thickness dimension of the sub-base element to the clearance dimension that may be additionally required so as to accommodate the drain pan.

The sub-base element 1 is oriented inside the depression 6 so that the upper edge 10 of the outside contour of the sub-base element 1 ends flush with the upper edge 11 of the flooring level 26. Any differences in height that may be present are compensated for by shimming the sub-base element 1 with leveling elements 12 or with height-adjustable elements, which can include, for example, feet 14 equipped with an external thread, which can be screwed into the internal thread of threaded bushings 13, which are introduced in the lower face of the sub-base element.

The gap 21 extending between the sub-base element 1 and the floor covering 8 is filled with a joint mortar or a flexible joint sealant, and covered with a joint strip 22. A uniformly configured, flexible covering 28, which can be PVC for example, is applied to the surface of the floor covering 8 and the mortar layer 4 by means of an adhesive layer 29. The flexible covering 28 adapts to the surface contour located beneath. In the embodiment shown in FIG. 4, the surface of the flexible covering 28 is thus planar in the region of the floor covering 8 and in the region of the sub-base element 1 the angle β₂ is provided, forming a gradient toward the drain pan 9. The drain pan 9, which is introduced in the opening 5, is sealed to the flexible covering 28, at the bottom face of the top rim 23, with a sealant, which is not shown in detail.

FIGS. 5, 6 and 7 show different embodiments of the mortar reinforcements implemented in the graduation or bevel regions A. Region A can, for example, be designed with a graduation 25 (FIG. 5), with multiple steps (FIG. 6), or with a wedge shape (FIG. 7). However, polygonal shapes are also possible.

FIG. 7 moreover shows a reinforcement 20 which is introduced in the bevel region A and which can, by way of example, be an angle section 27. Such a reinforcement, or a different reinforcement, can be introduced in all graduation or bevel regions A.

LIST OF REFERENCE NUMERALS

-   1 sub-base element -   2 core layer -   3 non-woven fabric -   4 mortar layer -   5 opening -   6 depression -   7 unfinished floor -   8 floor covering -   9 drain pan -   10 upper edge -   11 upper edge -   12 leveling element -   13 threaded bushing -   14 foot -   15 ridge -   16 outside edge -   17 bevel -   18 ridge -   19 -   20 reinforcement -   21 gap -   22 joint strip -   23 upper rim -   24 transition layer -   25 graduation -   26 flooring level -   27 angle section -   28 flexible covering -   29 adhesive layer -   α₁ angle -   α₂ angle -   β₁ gradient angle -   β₂ gradient angle -   A region -   B region -   I-I intersecting line -   L_(A) outside edge length -   L_(I) inside edge length 

1. A sub-base element (1), for example a shower tray base element, for designing an overall floor-level system, the sub-base element (1) either being inserted in a depression (6) compatible therewith within a floor covering (8) having high pressure resistance, or the sub-base element being first placed on an unfinished floor (7) and the floor covering (8) having high pressure resistance, such as a floor pavement, then being applied adjoining the sub-base element, and the sub-base element having a layer structure as follows: a core layer (2) made of plastic foam, the pressure resistance of which is lower than that of the floor covering (8); a water-resistant transition layer (24), which is glued to the core layer (2) and comprises an adhesive layer containing a textile strengthening structure such as a non-woven fabric, a woven fabric or a laid scrim (3); and a highly pressure-resistant mortar layer (4) as the cover layer on the transition layer (24), the mortar layer being planar at the top or having a gradient, characterized in that the core layer (2), together with the transition layer (24) located thereon, is provided with at least one graduation (25), on at least one outside edge length (L_(A)), and/or on at least one inside edge length (L_(I)) of the sub-base element (1), and the mortar layer (4), which is planar at the top or has a gradient, is thickened in the region of the graduation (25) so that there is no significant difference in pressure resistance, or deformation resistance, between the surrounding floor covering (8) and the sub-base element (1).
 2. The sub-base element (1) according to claim 1, characterized in that the boundary region of the graduation (25) is made of the compacted material of the core layer (2).
 3. The sub-base element (1) according to claim 2, characterized in that the core layer (2), together with the transition layer (24) located thereon, on at least one outside edge length (L_(A)), and/or inside edge length (L_(I)) of the sub-base element (1), comprises an outwardly directed, wedge-shaped bevel (17; 19) instead of one or more graduations (25), and the mortar layer (4), which is planar at the top or has a gradient, is thickened in the region of the bevel (17; 19).
 4. The sub-base element (1) according to claim 3, characterized in that the angle of slope of the bevel (17) ranges between 10 and 45°.
 5. The sub-base element (1) according to claim 1, characterized in that the entire periphery of the sub-base element (1) is provided with one or more graduations (25), and therefore with a rim-side mortar thickening.
 6. The sub-base element (1) according to claim 3, characterized in that the entire periphery of the sub-base element (1) is provided with a bevel (17; 19), and therefore with a wedge-shaped, rim-side mortar thickening.
 7. The sub-base element (1) according to claim 1, characterized in that a load-bearing reinforcement (20) is introduced in the mortar layer (4) in the region of the graduation (25).
 8. The sub-base element (1) according to claim 7, characterized in that the reinforcement (20) is a mat or a material strip arranged in bundle form.
 9. The sub-base element (1) according to claim 7, characterized in that the reinforcement (20) is a plastic or metal rail.
 10. The sub-base element (1) according to claim 9, characterized in that the plastic or metal rail is cut to size from an angle section (27).
 11. A kit, comprising a sub-base element (1), for example a shower tray base element, for insertion into a depression (6) that is compatible with the sub-base element, in a flooring level (26) having a high pressure resistance floor covering (8) surrounding the depression (6), wherein the sub-base element (1) has a layer structure as follows: a core layer (2) made of plastic foam, the pressure resistance of which is lower than that of the aforementioned floor covering (8); a water-resistant transition layer (24), which is glued to the core layer (2), wherein the core layer (2), together with the transition layer (24) located thereon is graduated or beveled toward the outside, on at least one edge length (L) of the sub-base element (1); and a packaged mortar substance for mixing, which is to be applied on-site to the core and transition layers (2; 24) as mortar paste, and which results in a highly pressure-resistant mortar layer (4), which is planar at the top or has a gradient, as the cover layer on the transition layer (24), a mortar layer (24) being obtained in the region of the graduation that is thickened in a wedge shape, so as to preclude an excessive difference in pressure resistance between the flooring level (26) and the sub-base element (1).
 12. The sub-base element (1) according to claim 6, characterized in that a load-bearing reinforcement (20) is introduced in the mortar layer (4) in the region of the bevel (17); (19). 